But some of the effects weren't very interesting, and in general I wish more of the effects had been able to appear on different kinds of weapons.
I agree. It is probably for the best that they have absorbed the different effects into the different gun companies. It gives more room to make unique guns instead of 'gimmick' weapons like last game. Now how well it translates in the full game we will have to wait and see but I just hope Maliwan isn't going to be the primary gun of choice like it was for many last game.